399863 has 4 divisors (see below), whose sum is σ = 401568. Its totient is φ = 398160.

The previous prime is 399853. The next prime is 399871. The reversal of 399863 is 368993.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 368993 = 31 ⋅11903.

It is a cyclic number.

It is not a de Polignac number, because 399863 - 2¹² = 395767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431 + ... + 992.

It is an arithmetic number, because the mean of its divisors is an integer number (100392).

2³⁹⁹⁸⁶³ is an apocalyptic number.

399863 is a deficient number, since it is larger than the sum of its proper divisors (1705).

399863 is a wasteful number, since it uses less digits than its factorization.

399863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1704.

The product of its digits is 34992, while the sum is 38.

The square root of 399863 is about 632.3472147484. The cubic root of 399863 is about 73.6722171403.

The spelling of 399863 in words is "three hundred ninety-nine thousand, eight hundred sixty-three".